[vortex] 3c905C: Packet losses, but only with a switch (2nd part)

[Bogdan Costescu]

On Tue, 4 Jul 2000, Giuseppe Ciaccio wrote:

> mii-diag says:
> 
> Basic registers of MII PHY #24:  3000 782d 0040 6176 05e1 45e1 0003 0000.
>  Basic mode control register 0x3000: Auto-negotiation enabled.
>  You have link beat, and everything is working OK.
>  Your link partner advertised 45e1: Flow-control 100baseTx-FD 100baseTx
> 10baseT-FD 10baseT, w/ 802.3X flow control.

What you have there and I don't have here is a switch capable of flow
control. I don't know if this is treated transparent to the driver or we
have to take care of this in the driver. Can you disable flow control on
the switch ? (as the docs for the card say: "Advertise pause capability:
This bit is always set to on.").

> But the packet loss persists :(

How do you observe the packet loss? And how many packets are lost?

> And, even worse, it now occurs also with a crossover cable, as well as
> with a repeater hub.

What does mii-diag report in these cases?

> My feeling is that the autoneg is somehow broken in the 3c905C cards.

I'm using quite a lot of them and never had problems (after setting them
to "HAS_NWAY")...

> When enabled, it fails when connecting to non-negotiating devices (like the
> crossover cable and the repeater hub).  

I have used this (by forcing the switch to 100-FD and 100-HD) and the card
always went to the right mode. And with the crossover cable, it has also
an autonegotiating partener as the cable does nothing WRT this; or you
tried to connect to a card with forced speed?

> When disabled, it somehow still tries to work (with odd results) when
> connecting to a negotiation-capable device (like my switch), even if the
> device is instructed not to negotiate.

For me it also worked, both devices being set to either 100-FD or
100-HD...
I have 3C905C cards and a BayStack 350-24T switch.

Sincerely,

Bogdan Costescu

IWR - Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen
Universitaet Heidelberg, INF 368, D-69120 Heidelberg, GERMANY
Telephone: +49 6221 54 8869, Telefax: +49 6221 54 8868
E-mail: Bogdan.Costescu@IWR.Uni-Heidelberg.De